This invention relates generally to compensating heads of the type used with a bridge structure provided above a table which supports the glass to be scored, and deals more specifically with a head having pressure rollers which follow the glass surface contour, and support structure for the scoring tool capable of compensating for variations in this contour. More particularly, this invention relates to a bi-directional scoring tool which permits scoring in one and an opposite direction, and the scoring head to be described also includes means for rotating the structure for supporting the scoring wheel between mututally perpendicular directions such that the support body of the head need not be removed from the bridge structure in order to score in at least four different mutually perpendicular directions.
Prior art glass scoring heads have been provided with the capability of accommodating variations in the flatness of the glass being scored, but generally such prior art cutting heads have employed the use of levers and adjustable springs in rather cumbersome structures of the type shown and described in U.S. Pat. No. 3,280,677 to Grzymislawski, and U.S. Pat. No. 4,098,155 issued to Insolio.
The general aim of the present invention is to provide a more compact compensating head for a glass cutter such that no projecting levers or the like are required, and which head utilizes fluid pressure to achieve the capability of retracting and extending both the cutting wheel and associated pressure rollers, with particular advantage being taken of the concept of providing a pendulously supported glass scoring wheel in a pillar post which may be generally similar to that described in my co-pending application entitled "Glass Cutter" filed Nov. 9, 1978 and assigned Ser. No. 959,329 now U.S. Pat. No. 4,201,104.
In addition to the general aim of the present invention, that is to provide a bi-directional glass cutter with a self-castering action achieved in one and an opposite direction in a glass scoring head of the compensating type, still another aim of the present invention is to provide in such a compensating head the capability of rotating the structure supporting the glass scoring wheel and the pressure rollers so that scoring can be achieved in mutually perpendicular directions, both of which directions have the self-castering feature mentioned previously, and therefor providing a compensating head which will permit scoring of glass in at least four different directions related to these mutually perpendicular lines of action.
In summary, a compensating head of the present invention is well adapted for use in scoring sheet glass laid flat on a table or the like, particularly when the surface of the glass to be scored may not be perfectly flat, or when the bridge structure upon which the head is mounted may itself deflect in different amounts dependent upon the distance between the head and the support for such bridge structure. The apparatus of the present invention preferably comprises a generally rectangular support body adapted for movement in a plane generally parallel to the glass to be scored somewhat similar to that described in a co-pending application entitled "Compensating Glass Scoring Head" Ser. No. 039,858 filed May 17, 1979. Whereas said application describes a rectangular support body adapted for being mounted in any one of four possible positions to a bridge structure or the like, the present invention obviates the need for alternatively mounting the support body in these four different positions, and instead provides suitable means for scoring glass in four different directions, related perpendicularly to one another as a result of the novel structure to be described. A piston means of annular configuration is reciprocably provided in the support body, and more particularly in a cylindrical cavity defined therein, being adapted for limited movement on a line oriented perpendicular to the plane of the glass to be scored. Biasing means is provided to urge the piston means toward the glass, and glass engaging pressure rollers are mounted on this piston means, one on either side of the glass scoring wheel. The glass scoring wheel is reciprocably mounted within the annular piston means on suitable support means such that it too is adapted for limited movement on the same line of action as that of the piston means. The glass scoring wheel support means includes holder means rotatable on this same line of action. A downwardly open slot in the holder has spaced inner stop surfaces at the upper boundary of the slot such that a pendulum, pivotally supported in the slot, is adapted to abut these stop surfaces to define limits for its pendulous movement and to define two distinct positions such that the castering action required in a glass scoring pillar post is required without reversing the direction of motion for the pillar post and its associated support structure. The pendulum is of course pivotally supported for movement on an axis which intersects the line of action referred to above, and the glass scoring wheel is provided in the lower end of the pendulum for rotating on an axis parallel to the pendulum axis. The cutting wheel axis will be spaced rearwardly of the pendulum axis, and the said line of action, as a result of rolling contact between the wheel and the glass to be scored. Spring biasing means acts between the annular piston means and the scoring wheel support means, which spring biasing means provides a force independent of vertical movement of the pressure rollers as they travel across the surface of the glass being scored. Further, the piston means is rotatably supported in the support body, and may be rotated through a predetermined angular displacement (preferably 90 degrees) to align the glass scoring wheel with the intended direction of motion of the support body with respect to the glass during a scoring operation. The mutually perpendicular positions for the glass scoring wheel can be adjusted with accuracy by means of adjustable stop screws acting on cams provided for this purpose in the support body. These cams are slidably received on the annular piston so as not to interfere with the reciprocating motion of the piston while the screws are threadably received in the support body itself.